In certain cases you might want to add a command line parameter when you start OOTP. There are the following parameters available:
 
tracemode - enables trace mode. Certain information will be written into a file ootp.log
 
nofacegen - disables facegen
 
debugfacegen - creates some images in the /facegen folder which can help to find facegen problems. The folder is usually My Documents\Out of the Park Developments\OOTP Baseball 9\data\facegen, and the file names are  debug_*

continue_current_league - automatically opens the current league
 
-unlicense - this is actually an eLicense parameter, not an OOTP parameter. It will open the unlicense dialog for the game when you start it.

First make a copy of the icon which you're using to start OOTP: Right click on the icon and click on Copy. Right click on the Windows desktop and click on Paste.
You can rename that icon, for example "OOTP with tracemode".
Right click on the icon and select "Properties". There is a command line in that dialog which ends with "ootp200.exe". Click into the text box and use your cursor keys to go to the end of the line. Add the parameter(s) there, separated by spaces. For tracemode, the command line will look like this:
 
"C:\Program Files\Out of the Park Developments\OOTP Baseball 9\ootp2009.exe" tracemode
 
Please note that the parameter is behind the quote.
Save the changes and click on the icon to start OOTP, using the parameter.